Electric time switches



Sept. 15, 1959 K. J. HORSTMANN ETAL 2,904,648

ELECTRIC TIME SWITCHES Filed Dec. 1:, 1957 2 Sheets-Sheet 1 L. G. M.PfiY/WS' Sept. 15, 1959 K. J. HORSTMANN ETAL 2,904,648

ELECTRIC TIME SWITCHES Filed Dec. 13, 1957 2 Sheets-Sheet 2 UnitedStates Patent ELECTRIC TIME SWITCHES Kenneth John Horstmann and LeslieGeorge Mountjoy Payne, Bath, England Application December 13, 1957,Serial .No. 702,672

Claims priority, application Great Britain December 14, 1-956 '5 Claims.(Cl. 200-38) This invention relates to electric time switches of thetype used for making or breaking electric circuits, for example electriclighting circuits, at predetermined times of the night or day. 'Iimeswitches of the type referred to herein comprise a dial plate rotatedperiodically and carrying members-referred .to herein as tappets which.are ,adjustably positioned around the dial plate circumference andadapted selectively to actuate an electric switch mechanism, at leastone of the said tappets being adapted to set the switch to its onposition and at least one other of the said tappets being adapted to setthe switch to its off position.

Time switches of this type are described in Horstmanns prior Britishpatent specifications Nos. 329,633, 331,083, 373,554 and 500,670.

One switch actuating mechanism advantageously used in time switches ofthis type has two levers, which are selectively engaged by the tappetsreferred to above, one of which levers trips the switch to the onposition and the other of which trips the switch to the off position.

In normal operation of the time switch, the two levers are engagedalternately, since it will be understood that if one operation is toswitch a circuit off, the next operation will be to switch it on.However, circumstances may arise in the use of the time switch resultingin the actuation twice in succession of one or other of the two leversand this may cause the switch to be actuated slowly with consequentarcing at the contact points thereof.

The object of the present invention is to overcome this difiiculty.

According to the present invention, an electric time switch of the typedescribed has a lever which is selectively engaged by the said tappetsand moved by the rotation thereof to set the switch to one of its saidpositions and a retaining catch which is set by the movement of the saidlever to hold the switch in the said one position in the event of asecond engagement of the said lever before the switch is set to itsother position.

In order that the invention may be readily carried out, a practicalembodiment will be particularly described, by way of example, withreference to the accompanying drawings of which:

Figure 1 is a front view of an electric time switch of the typedescribed;

Figure 2 is a view from above of the time switch of Figure 1, showingthe switch actuating mechanism;

Figure 3 is an exploded, isometric view of the switch actuatingmechanism shown in Figure 2; and

Figure 4 is a back view of the time switch of Figure 1.

In Figure l, the electric time switch comprises a dial plate 1, carrying24-hour graduation marks 2, removably mounted on a spindle by which itis rotated once in 24 hours by a synchronous electric motor. Thesynchronous electric motor and suitable reduction gearing are housed inthe rear part of a cylindrical casing 3. These parts of the time switchare of known form and are not illus- 2 trated in the drawings. Furtherdescription of them is not necessary for an understanding of the presentinvention.

The dial plate 1 is housed in the front part .of the casing 3 slightlyforward of a plate 4 carrying the switch actuating mechanism describedbelow. The dial plate It carries two tappets 5 .and 6, the outer ends ofwhich are shown in Figure l. The tappets 5, 6 are angularly settablerelatively to the dial plate 1 and are rotated thereby so that theyaresimilarly rotated once in 24 hours.

The tappets 5, 6 are provided with graduated sector plates 7, 8respectively which are angularly adjustable relatively to the dial plate1 and are locked by screws 9, 10 respectively.

The sector plate 7 of tappet 5 carries a rearwardly extending pin 11arranged to engage a lever 12 and to trip the :switch to the offposition. The lever is referred to as the cit trip lever. The sectorplate 8 of tappet 6 carries a forwardly extending pin 13 arranged toengage a bell crank lever 14 and to trip the switch to the on position.The lever lever.

The remainder of the switch actuating mechanism will now be describedwith reference to Figures 1 and 2, which show the mechanism assembled,and to the exploded View of Figure .3. The bell crank lever 14 iscarried on a pivot .15 on the casing plate 4 and has a trip arm 14'extending towards the :dial plate 1 for engagement by the on .tappet anda second arm 1-4 in which is secured a bush .16. The bush 16 receives apivot pin 19 of a pawl 17 having a forked end 18 and a (first)v catch.20 for a switch actuating lever 34. The forked end 1 8 of pawl 17engages a forwardly extending pin 22 attached to the lever 12. The lever12 has a rearwardly: extending pivot pin 21, about which lever 12pivots, and which is received in a bush .23 in the casing.

plate 4. The lever 12 is also provided with a forwardly extending pin 24for engagement by the off tappet 7; a manual operation arm 25 with itsend turned over and rearwardly extending and a rearwardly extendingdisen herein as the second catch. The other end 27" of pawl 27 isnotched at 30 to receive one end of a light tension spring .31, theother end of which spring is held by a pin 32 on the casing plate 4.

A switch actuating lever 34 has a bush 35 at one end by which the lever34 is pivoted about an internally threaded pillar 36 mounted on thecasing plate 4. The lever 34 has a forwardly extending arm 37 reducednear its forward end to receive one end of a tension spring 38, theother end of which spring is attached to a pin 39 on the first catchpawl 17. The lever 34 also has a forwardly extending latch arm 40arranged to bear on the catches 20 and .29 in the manner to bedescribed.

A three-armed member 41 carries a bush 42 which fits over the bush 35 oflever 34. The member 41 comprises a short arm 41, which abuts againstthe arm 37 of lever 34, a longer arm 41" which abuts against the arm 25of lever 12 and a forwardly bent arm 43 which extends.

The cover carries an adjustable index 47 against which the dial plategraduation marks 2 are read. The pillar 46 also serves as a. stop forthe clockwise rotation of the bell crank lever 14 which is operated bythe on tappet 6.

14 is referred to as the on trip As shown most clearly in Figure 2, theswitch actuating lever 34 carries a rearwardly extending pin 48 whichextends through a circular aperture 49 in the casing plate 4. At itsend, the pin 48 carries a button 50 of insulating material which engageswith the switch contact arm 60.

Referring now to Figure 4, the casing plate 4 carries on its rear face ahousing 51 of insulating material in which are mounted two heavy contactpins 52, 53 and a lighter contact pin 54 arranged to fit into a suitablesocket, not shown. The pin 54 carries a clip 55 to which is attached onelead 56 of the synchronous driving motor. The other lead 57 is attachedto a terminal 58. To the base of pin 53 is brazed a contact point 59 andto the base of pin 52 is brazed a spring contact arm 60 carrying acontact point 61.

The button 50 is arranged to deflect or release the switch arm 60,according to the movement of lever 34, thereby respectively opening orclosing the switch contact points 59, 61.

In the operation of the time switch, rotation of the dial plate 1brings, say, the pin 13 of the on tappet 6 into engagement with the arm14 of the bell crank lever 14. Continued rotation of the dial plate 1then carries along the arm 14 producing counterclockwise rotation of thebell crank lever 14. This rotation simultaneously tensions spring 38 anddraws downwardly the first catch pawl 17 partially disengaging the fork18 from the pin 22 until the first catch passes the left hand edges ofthe latch arm 40 of lever 34. At this point, the pawl 17 is rotatedslightly in the clockwise direction by the tension of spring 38 so thatthe catch 20 engages the latch arm 40.

Further rotation of the dial plate 1 carries the on tappet and the triparm 14' along divergent arcs until the end of trip arm 14' is free ofpin 13. Thereupon the bell crank lever 14 is released and, under tensionof spring 38 transmitted through pawl 17 and pivot pin 19, is rotatedquickly in the clockwise sense until it is arrested by pillar 46. Bythis rotation, the pawl 17 is moved upwards again but, since the firstcatch 20 is now engaging the latch arm 40, the switch actuating lever 34is rotated in the counterclockwise sense moving the button 50 upwardsand allowing the switch contact points 59, 61 to close.

The switch actuating lever 34 is biased to rotate in the clockwisesense, however, by the tension of spring 38 but, as indicated, is heldagainst such rotation by the first catch 20, and the second catch 29 oflever 27 when in this position.

It has been convenient to describe the operation of the time switch sofar by assuming a simple dial plate assembly carrying one fixed ontappet and one fixed oft tappet. However, in practice, this assembly maycomprise more than one of each kind of tappet and, particularly, maycomprise means for progressive angular adjustment of the various tappetsin operation as provided by the solar dial described in HorstmannsBritish prior patent specification No. 744,612.

Supposing now that the action of such a time switch brings a second ontappet into engagement with the trip bell crank lever 14. The movementtransmitted therefrom to the button 50 will cause the contact arm 60 tobe moved slowly downwards and, if permitted to continue, this motionwould cause the slow separation of the contact points 59, 61. Suchundesirable motion is prevented by the second catch 29, which is afeature of the present invention.

Returning now to the embodiment shown in the drawings, upon the releaseof arm 14' from on tappet pin 13, and the upward movement of pawl 17,the latch arm 40 is carried upwards past the lip of the second catch 29.Thereupon, the double-ended lever 27 is rotated in the clockwise senseby the tension of spring 31. The catch 29 thus moves into the downwardpath of the arm 40 and, if the switch actuating lever 34 were releasedto rotate in the clockwise sense by the action of a second on tappet asdescribed above, such movement is arrested by the abutment of latch arm40 against second catch 29 before the switch contacts are opened.

Upon engagement of pin 11 of the off tappet 5 with lever 12, the latterlever is rotated in the counterclockwise sense about its pivot pin 21.Pin 22 thereupon engages the left arm of fork 18 to rotate pawl 17similarly against the tension of spring 38. When pawl 17 is sufficientlyrotated, first catch 20 becomes disengaged from latch arm 40 so that theswitch actuating lever 34 is released and rotates clockwise undertension of spring 38 until arm 40 is arrested by catch 29.

Also, upon counter-clockwise rotation of lever 12, disengagement lug 26engages arm 27 of lever 27 so that lever 27 is similarly rotated in thecounterclockwise sense. Upon further rotation of lever 12, thecorresponding rotation of lever 27 by lug 26 causes the second catch 29to become disengaged from latch arm 40 so that switch actuating lever 34is released to rotate clockwise under action of spring 38 so that button50 moves the switch contact arm 60 quickly to the open position of theswitch. After further rotation the off tappet pin 11 disengages from thelever 12 whereupon the lever 12, lever 27 and pawl 17 all rotate in theclockwise sense, under the tension of spring 38 applied to pin 39 and ofspring 31, until the edge of pawl 17 and lever 27 are arrested by theedge of latch arm 40. The switch actuating mechanism is then reset forsubsequent on actuation.

The time switch described further operates to prevent a slow break ofthe switch contacts 59, 61 when on and off tappets are set very closetogether. This close setting of the tappets can occur, for example, bythe operation of a solar dial.

The solar dial described in British patent specification No. 744,612 hasan early morning on tappet. With certain settings of the midnight oiitappet, approximately 1:00 a.m., and with the early morning on tappetset to give the maximum early morning lighting period,

' approximately 1% hours, this on tappet is moved back towards midnightby the solar off tappet and may pass and actually be positioned beforethe midnight off tappet. Under such conditions, the on and ofi levers 14and 12 respectively move together. Such movement does not result inambiguous operation of the switch mechanism, however, due to the shapeof the right hand edges of pawl 17, lever 12 and lever 27, as seen inFigure 3. It is particularly to be noted that the second catch 29 onlever 2'7 projects further to the right than does the first catch 20 ofthe pawl 17. The second catch 29 is thus always the controlling catch insuch circumstances so that switch actuating lever 34 is always releasedclearly and sharply, under the action of spring 38, to its extremedownward position thereby opening the switch contacts 59, 61 quickly.

The forwardly extending arm 43 of multi-armed lever member 41 providesfor manual operation of the switch. Movement of the arm 43 to the leftin the slot 44 (Figure 2) causes arm 41 to bear against the turned overend of arm 25 on lever 12. This action rotates the pawl 17,

lever 12 and lever 27 in the counterclockwise sense releasing in turnthe two catches 20 and 29 so allowing the switch actuating lever 34 torotate clockwise under the action of spring 38 to open the switchcontacts 59, 61. Movement of the arm 43 to the right in slot 44 causesarm 41 to bear against arm 37 of switch actuating lever 34 which isthereby lifted to allow the switch contacts 59, 61 to close. During thismovement of lever 34, the catches 2t 29 move into their positions ofengagement as described.

We claim:

1. An electric time switch of the type comprising a dial plate rotatedperiodically and carrying on and oft" tappets which are adjustablypositioned about the dial plate circumference for actuation of switchmechanism, wherein said switch mechanism comprises spring controlledswitch contacts, an actuating lever controlling said contacts, first andsecond catches controlling said lever, means whereby the on tappet movessaid lever through the first catch to close the switch contacts andpositions the second catch to lock the said lever in the switch closedposition, and means operable by the ofi tappet first to release bothcatches, the first in advance of the second from said lever whereby theswitch contacts open, and thereafter to reset the catches for subsequenton operation of said switch mechanism.

2. An electric time switch according to claim 1, where in saidrespective means comprise an on trip lever having one arm in the path ofthe on tappet, a forked pawl lever pivoted on another arm of said ontrip lever, and carrying said first catch, a fixed pivot, and off triplever operable by the ofl? tappet and pivotal on the fixed pivot, saidoh. trip lever having a member engaging in the fork of said pawl, asecond catch carrying lever having the second catch thereon and pivotedon said fixed pivot, a latch arm on said actuating lever, said catchesbeing juxtaposed to said latch armwith the second catch longer than thefirst and arranged such that said second catch engages with anddisengages from said latch arm after the first catch, and spring meansnormally biassing said trip and catch carrying levers to the resetposition.

3. An electric time switch of the type comprising a dial plate rotatedperiodically and carrying on and off tappets which are adjustablypositioned about the dial plate circumference for actuation of switchmechanism, wherein said switch mechanism comprises spring controlledswitch contacts, an actuating lever controlling said contacts, first andsecond catches directly controlling said lever, separate trip leversadapted for displacement by the on and off tappets respectively,separate catch levers carrying said catches respectively, andconnections be tween said catch levers and said trip levers wherebydisplacement of the on trip lever moves said first catch in advance ofthe second catch to cause the switch actuating lever to close saidcontacts, and subsequent displacement of the off trip lever disengagessaid first catch in advance of the second catch from the actuating leverto close the switch contacts and reset the levers in the normal onposition.

4. An electric time switch according to claim 3, wherein saidconnections include a fixed pivot and a multiarm lever pivotal inopposite directions on said fixed pivot for manual operation of saidactuating lever, one

arm being an operating arm, another arm co-operating with the ofi triplever to effect displacement thereof to the off position when the manuallever is moved in one direction whereby to effect release of the firstand second catches in turn from said actuating lever to open the switchcontacts, and a third arm co-operating directly with said actuatinglever to move it to the switch closed position when the manual lever ismoved in the opposite direction.

5. An electric time switch of the type comprising a dial plate rotatedperiodically and carrying on and off tappets which are adjustablypositioned about the dial plate circumference for actuation of switchmechanism, wherein said switch mechanism comprises spring controlledswitch contacts, an actuating lever controlling said contacts, first andsecond catches controlling said lever, a mounting plate having a firstpivot carrying said actuating lever, a second pivot and a third pivot,an on trip lever having one arm in the path of the on tappet, andpivotal on the second pivot, a forked pawl lever pivotal on another armof said on trip lever and carrying said first catch, an oil trip leverpivotal on said third pivot and having one arm in the path of the offtappet, a member on said 01f trip lever engaging in the fork of saidpawl, a second catch carrying lever having the second catch thereon andpivotal on said third pivot, a latch arm on said actuating lever, saidcatches being juxtaposed to said latch arm with the second catch longerthan the first and arranged such that said second catch engages with anddisengages from said latch arm after the first catch, and spring meansnormally biassing said trip and catch carrying levers to the resetposition, and a multi-armed manual lever mounted on said first pivotwith two of its arms co-operating with the said actuating lever and offtrip lever respectively to efifeet displacement of the actuating leverto switch open and closed positions by opposite pivoted displacements ofthe manual lever.

References Cited in the file of this patent UNITED STATES PATENTS2,034,178 Flegel Mar. 17, 1936 2,176,569 Gillette Oct. 17, 19392,217,414 Lenehan Oct. 8, 1940 2,300,513 Lenehan Nov. 3, 1942 2,662,943Morrison Dec. 15, 1953 2,723,320 Harris Nov. 8, 1955 2,832,856 GoodhouseApr. 29, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No, 2,904,648 September 15, 1959 Kenneth John Horstmann et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrested below, I

In the grant, lines 1 and 2, for "Kenneth John Horstmann and LeslieGeorge Mountjoy, of Payne, Bath, England," read Kenneth John Horstmannand Leslie GeorgeMountJoy Payne, of Bath, England, line ll, for "KennethJohn Horstmann and Leslie George Mountjoy, their heirs" read KennethJohn Horstmann and Leslie George Mountjoy Payne, their heirs Signed andsealed this 29th day of March 1960,

(SEAL) Atfiest:

KARL AXLINE ROBERT c. WATSON Attesting Officer Comnissioner of PatentsUNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent N092,904,648 September 15, 1959 Kenneth John Horstmann et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below,

In the grant, lines -1 and 2, for "Kenneth John Horstmann and LeslieGeorge Mountjoy, of Payne, Bath, England," read Kenneth JohnHorstmannand Leslie George Mountjoy Payne, of Bath, England, line 11,for "Kenneth John Horstmann and Leslie George Mountjoy, their heirs"read Kenneth John Horstmann and Leslie George Mountjoy Payne, theirheirs Signed and sealed this 29th day of March 1960.,

(SEAL) Atfiest:

KARL AXLINE ROBERT c. WATSON Attesting Officer 7 Comnissioner of Patents

